Method of drilling hard materials



June 3, 1969 R. ANNEN METHOD OF DRILLING HARD MATERIALS Filed May 25, 1967 INVENTOR Robert Annen Y PRIOR ART ATTORNEY United States Patent O US. Cl. 125-30 1 Claim ABSTRACT OF THE DISCLOSURE A method used in the drilling of hard materials, e.g. watch and clock makers jewels, including the steps of, disposing a pair of drill-carrying spindles in coaxial oppositely-moving directions "and on opposite sides of a fiexible vibratable jewel-carrying blade, and drilling the jewel from its opposite sides while simultaneously vibrating the blade and jewel carried thereby.

CROSS REFERENCES TO RELATED APPLICATIONS This is a continuation-in-part of my copending application, Ser. No. 404,292, filed Oct. 16, 1964, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to a drilling method for the drilling of hard materials, such as watch and clock makers jewels.

Description of the prior art Known prior art includes Moses, #2,402,831 of June 25, 1946, which teaches a mechanism :for the piercing of refractory bodies such as are used in the manufacture of wire drawing dies. Such mechanism allows the making of a die opening of a definite diameter through the axis of a die b'ody.

Kurtz, #2,377,l59, of May 29, 1945, teaches a method and mechanism for drilling hard substances such as diamonds. Kurtz suggests the use of opposed drill spindles.

Simons, #2,332,609, of Oct. 26, 1943, and Peters et al., #2,622,581, of Dec. 23, 1952, teach the use of drilling machines.

What the prior art references seem to lack is a teaching of the technique of using opposite drills while vibrating.

SUMMARY OF THE INVENTION The method for the drilling consists in disposing a pair of spindles carrying drills in coaxial oppositely-moving directions and on opposite sides of a flexible vibrated jewel-carrying blade, and drilling the jewel from its .opposite sides while simultaneously vibrating the blade and the jewel.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a diagrammatic sectional view of a two spindle machine for drilling watch and clock makers jewels according to the method of the invention;

FIGURE 2 is a sectional view of one detail of the FIG. 1 machine, drawn to a larger scale;

FIGURE 3 is a plan view of the FIG. 2 detail drawn on the same scale; and

FIGURES 4 to 8 show the drilling process as it takes place when two coaxial spindles are used, but without vibration.

3,447,528 Patented June 3, 1969 DESCRIPTION OF THE PREFERRED EMBODIMENT The machine includes a pair of coaxial spindles 1 and 2 which revolve in bearings 3 and 4 respectively and are driven by air turbines 5 and 6 respectively. Each spindle carries a drill 7 or 8 respectively, the two drills being coaxial as to each other and directly opposed to each other. Spindle 1 operates by gravity, while spindle 2. is subject to the action of a lever 9 pivoted at 10 and hearing a counterweight 11 which exerts on this spindle an axial force which tends to move it upwardly.

A vibrating device includes a flexible vibrating blade 12 riveted to a sleeve 13 which is fitted on a fixed shaft 14 carried by a structural part '15 of the machine frame, the sleeve being clamped on shaft 14 by a knurled nut 16. The free end of blade 12 is guided by a fixed pin 17 carried by the machine frame, there being a differenceof about one tenth of a millimeter between the diameter of the hole in blade 12 through which pin 17 passes, and the diameter of the pin, to allow free movement of the end of blade 12 during the vibration thereof.

An electromagnet 18, supplied with current whose frequency can be modified as necessary, acts on vibrating blade 12 by means of a small plate 19 carried by said blade, so as to maintain the vibration of the latter.

Blade 12 bears a device, for fixing the object to be drilled thereon, which comprises a flexible clip consisting of a thin disc 20 fixed to the blade by screws 21 and cut out to provide a diametral bridge formed of two parts 20a and 20b separated by a diametral slot 22. The fixing device also comprises, at the center of disc 20, a collar 23 which is slotted diametrally so as to constitute two jaw-members 23a and 23b which are carried by the respective parts 20a and 20b of the diametral bridge and are intended to grip resiliently the object to be drilled, in this case a watch or clock makers jewel.

The parts of the fixing device, namely disc 20, jawmembers 23a and 23b carried thereby, and a small plate 24 located beneath disc 20 between the disc and blade 12, may be readily replaced by other parts of different construction according to the form of the object to be drilled and to be held-in position. For this purpose, it is sufiicient first to raise upper spindle 1 and then to undo knurled nut 16 and to remove vibrating blade 12 from shaft 14.

Moreover, the vibrations permit elimination of the inner lip which otherwise would be provided in the hole, as indicated in FIGURES 4 through 8.

As a matter of fact, when drills 7 and 8 are in good condition (FIGURE 4), their end faces, designated by 7a and 8a respectively, are plane, the drilling being effected by the abrasive action of the abrasive material which is previously placed on the two faces of the jewel to be drilled, and owing to the waste of the material of the jewel which constitutes also an abrasive material.

As indicated by FIGURES 5 through 7, the more the drilling operation is carried out, the more the terminal edge of each drill 'as indicated by 7b and 812 respectively, is rounded, and due to the wear, so that, when the two drills engage one another (FIGURE 7), they allow between them an annular lip 25a of the material of the jewel which is designated by 25. The thicker the jewel, the more wear of the drills and the higher the inner lip. For instance, in the case of a jewel of a thickness of mm. in which is drilled a hole of a diameter of mm., the height of the lip, at its base, will be of about A mm. Consequently, if the vibrating means is arranged in such a way that the amplitude of the vibrations be higher than the height of the lip, i.e. higher than mm. in the disclosed example, the vibrations eliminate the inner lip 250.

I claim:

1. In the drilling of hard materials, the method of,

3 disposing a pair of spindles carrying drills disposed in 00- axial oppositely-moving directions-and on opposite sides of a flexible vibrated jewel-carrying blade, and drilling the jewel from its opposite sides while simultaneously vibrating the blade and jewel carried thereby.

References Cited UNITED STATES PATENTS 2,332,609 10/1943 Simmons 125-30 4 2,377,159 5/1945 Kur tz 2 12530 2,402,831 6/1946 Moses 125-30 2,622,581 12/1952 Peters 12530 HAROLD D. WHITEHEAD, Primary Examiner.

US. Cl. X.R. 77-21 

